S. Creden1,2, A. Espinoza1,2, O. Olutoye1,2, T. Nack1,2, Y. D. Sevilmis1,2, I. Iacobas1,3, K. Rialon1,2 1Baylor College Of Medicine, General Surgery, Houston, TX, USA 2Texas Children’s Hospital, Pediatric Surgery, Houston, TX, USA 3Texas Children’s Hospital, Pediatric Hematology And Oncology, Houston, TX, USA
Introduction:
Lymphatic anomalies (LAs) are a highly variable clinical entity, including both discrete malformations and generalized anomalies. If a LA involves central collecting channels, chylous ascites (CA) may develop. Morbidity may be secondary to loss of intravascular fluid, chyle, and protein; mass effect; or frequent infections. Procedural interventions include percutaneous drainage, shunt placement, and/or surgical resection. Sirolimus, a mammalian target of rapamycin (mTOR) inhibitor thought to regulate angiogenesis and cell growth, has garnered attention as a treatment modality for LAs. The effect of sirolimus on CA in children has yet to be well characterized.
Methods:
A retrospective chart review was performed at single tertiary referral center with a multidisciplinary Vascular Anomalies Center from 2010 to 2022 of all patients under 18 years of age presenting with CA. Sirolimus was administered according to institutional treatment guidelines.
Results:
Sixteen patients were identified to have a LA with CA. Eleven patients possessed a generalized LA. Other diagnoses include GI lymphangiectasia with protein losing enteropathy, and non-immune hydrops. Three patients (19%) were noted to be premature. The median age at diagnosis was 5.5 months (interquartile range [IQR] 1 month – 36 months). The median age at sirolimus initiation was 8 months (IQR 1 month – 6 years). The most common medical therapies employed prior to initiating sirolimus were furosemide in 7 (44%) and octreotide in 7 (44%) patients. Nine patients required peritoneal drainage prior to initiating sirolimus. Following initiation of sirolimus, 5 patients (31%) required temporary interruption of administration due to infectious events. Of those 5, none survived (100% mortality). This is in contrast to 5 deaths among those with no complications of sirolimus treatment (5/11 = 45%). Two patients underwent lymphaticovenous bypass surgery, but only 1 was successful. Two patients underwent placement of a Denver Shunt. Following initiation of sirolimus, 8 (50%) showed stabilization or decrease in drain output, and 2 (22%) patients’ drains were removed. In the 5 patients that received sirolimus alone with no surgical intervention, 2 (40%) recovered; the other 3 (60%) did not survive. In those with chromosomal abnormalities (n=3), none survived. Of the 16 patients, there was a 63% mortality rate. The median age at initiation for surviving patients was 5 years, compared to 2 months for those that did not survive.
Conclusion:
In this medically complex pediatric population, over half of patients treated with sirolimus showed improvement. Mortality remains high in the overall population, particularly for those with a chromosomal abnormality, those that developed chylous ascites and required treatment in infancy, and those that required interruptions in the sirolimus administration due to infections.